Which bacteria digest the bacteria and fungi present in the sludge during sewage treatment?

Which microorganisms are responsible for the formation of flocs in sewage treatment?

Select the correct sequence with respect to sewage treatment.
$i$. Removal of suspended solid particles by primary treatment.
$ii$. Wastewater screening
$iii$. Anaerobic bacteria digest activated sludge.
$iv$. Treatment by flocs in aeration tank.
$v$. Grit settling

Sewage treatment is carried out by .........

Identify the stage of sewage treatment shown below.

In large cities,domestic sewage ............